1. Technical Field of the Invention
The present invention relates to the formulation of an antagonist of CGRP (peptide derived from the calcitonin gene: Calcitonin Gene Related Peptide, or "CGRP") into cosmetic/pharmaceutical/dermatological compositions, in particular for topical application, for treating rosacea and/or discreet erythema.
More especially, this invention relates to the topical, ingestible or injectable treatment of rosacea or discreet erythema.
2. Description of the Prior Art
It is known to this art that rosacea is a skin affliction characterized by erythema of the face, predominantly on the cheeks, the forehead and the nose, hyperseborrhoea of the face on the forehead, the nose and the cheeks, and an infectious component manifesting acneiform pustules.
Moreover, these indications are associated with a neurogenic component, namely, a cutaneous hyperreactivity of the skin of the face and of the neck, characterized by the appearance of redness and subjective sensations of the itching or pruritus type, sensations of burning or of heating, sensations of stinging, tingling, discomfort, tightness, etc.
These signs of hyperreactivity may be triggered by very varied factors such as the intake of food or of hot or alcoholic drinks, by rapid temperature variations, by heat and in particular exposure to ultraviolet or to infrared irradiation, by a low relative humidity, by exposure of the skin to strong winds or to currents of air (conditioned air, fans and blowing machines), by the application of surfactants, irritant dermatological topical agents (retinoids, benzoyl peroxide, alpha-hydroxy acids, etc.), or the use of certain cosmetics, even when these are themselves not recognized as being particularly irritating.
Hitherto, the mechanism for triggering these indications was very poorly understood and rosacea was treated with active agents such as anti-seborrhoeic agents and anti-infection agents, for example benzoyl peroxide, retinoic acid, metronidazole or cyclins, which act on infection and hyperseborrhoea but do not permit the neurogenic component of this affliction, and in particular hyperreactivity of the skin and redness, to be treated.
Similarly, hitherto no treatment existed for the redness which develops in discreet erythema. This latter affliction occurs at times of emotion and is characterized by redness of the face and neckline, which possibly may be accompanied by pruritus (itching). This condition is very irritating for individuals suffering therefrom, and to date it could only be treated by beta-blockers, powerful drugs used for treating hypertension and exhibiting many contra-indications.
Thus, serious need continues to exist in this art for an effective treatment of skin redness and of the state of hyperreactivity of skin affected by rosacea or discreet erythema.